Bidirectional Cuk converter input/output impedance

[Ahaad3001]

How to find the impedance model(input and output) of a bidirectional cuk converter? I have been working of buck/boost converter but unfortunately got stuck with the bidirectional cuk converter. My design is for a static heat waste recovery for modern vehicles. all responses are most appreciated and thank you guys in advance, hope i may get some help from here

 

[ArticCynda]

Welcome to the forum!

Could you explain how the cuk converter can be used for waste heat recovery? A better understanding of the problem will lead to more accurate suggestions.

 

[Ahaad3001]

do you know how TEGs are used in vehicles to convert the waste heat energy to electrical?
The idea is to capture the heat energy, and transform it to electrical energy to be used within the vehicle itself.
so from the TEG to the DC bus of the vehicle system, it goes across two converters, namely, two switch buck/boost and the bidirectional converter, with a supercapacitor connected to it.

 

[mtwieg]

First you should find the state space model for the converter itself (can be found in literature for CCM operation). Impedances will of course depend on specific controller, so that must be known as well. Then you can model the closed loop impedances by rearranging the state space model and perturbing it with voltage and current sources.

 

[Orson Cart]

I don't see how your Cuk converter needs to be bi-directional unless you plan to put energy back into your TEG...?
a unidirectional converter would be OK for energy to the battery only.
Post your Cuk ckt with values and it will be easy to give you an idea of impedance (open loop) with freq, looking in to the output and in to the input...